Non-surface contact: X, Y, Z motions
Surface contact: Z only!
Sample loading time: 2-3 sec
Pin wash time: 3 cycles at 1-3 sec/cycle
Z axis surface clearance: 1.0-1.5 mm
Z axis acceleration: 30 cm/sec2
Z axis velocity: 7.5-20 mm/sec (See Table 1)
Z axis travel (surface = 0): +0.5-1.0 mm
Surface dwell time: 0.05 sec
Cycle time (32 pins): 32 features/sec

*All motion control parameters are suggestions only. Each of these parameters should be empirically tested with a single spotting pin to test printing quality and pin durability. Parameters can be modified to maximize printing quality and speed in a manner compatible with your motion control system. Changes in Z axis surface clearance, acceleration, velocity and travel should be made with extreme care!

The Stealth Microarray Spotting Device is designed and engineered for optimal wear and durability, while gaining the highest printing performance in the sub-nanoliter scale. The Pins and Printhead have been tested out to 1 million printing cycles with no loss of printing precision or performance. Maximum durability requires proper use. Improper use of these precision products can lead to loss of performance or permanent damage. To avoid damaging your Stealth Micro Spotting Device, please follow these guidelines:

1. The Printhead should be mounted on the motion control system prior to inserting the Pins into the Printhead. All hardware, motion control movements, calibration and software should be completely checked prior to inserting the Pins into the Printhead. Once the Pins are carefully inserted into the printhead, Pins can be damaged by inappropriate use. Pins must never be dropped, slammed or dragged across solid surfaces. Any contact of this nature outside the Z-axis will permanently damage the tips of the Micro Spotting Pins. Pay particular attention to the Z-axis speed settings and use the recommended setting in this protocol.

2. If a loss of printing quality is observed, the spotting pins can becleaned by carefully by using the Pin and Printhead Cleaning Kit. Never subject Stealth parts to extremes in temperature or pH and avoid the use of strong solvents as these may damage the pin surface chemistry. Never dry Pins using canned air, the propellants ruin the surface tension properties needed for reliable printing. To clean Pins use the Pin and Printhead cleaning kit.

3. Microarray experiments depend upon the quality of the samples. Samples prepared by standard purification procedures can result in pin clogging and a loss of chip quality. For best results with PCR products use PCR products purified with one of the ArrayIt® PCR Purification Kits. Increased performance can also be obtained by using spotting buffers and surface chemistry specifically formulated for optimal results.

4. WARNING: Pressurized air cannisters and other sources of pressurized air contain organic propellants that ruin the surface tension properties of pin tips. Do not use pressurized air cannisters to dry your pins!! Use the Microarray Air Jet for this purpose.

The keys to a wash/dry station working properly are:

(1) A clean and continuous distilled water source that does not splash or aspirate

(2) Sufficient vacuum airflow to dry the printing mechanisms, and

(3) Proper motion control programming.

Wash water should be continually replenished during a print run to avoid build up of residual sample. A build up of sample could cause serious cross contamination of samples. A vacuum dry station does not rely on vacuum pressure to dry printing tips, it relies on a large amount of air passing over the tips to facilitate drying. Multiple wash/dry cycles are necessary to make sure that all residual samples are washed away. A common error in programming a wash/dry cycle is drying the tips of the printing mechanism too long after the first wash cycle. Only dry completely after the last wash cycle. If any residual sample is on the tip and it is dried there, it is much harder to wash away. The result is poor printing performance and/or cross contamination of sample.

Nominal Stealth Pin dimensions are as follows: length = 1 1/16 inches (26.99 mm), diameter = 1/16 inches (1.59 mm), and weight = 0.4 grams. Stealth Pins are named using a prefix, number and suffix (if any) as follows: SMP3XB, SMP (Stealth Micro Spotting Pin); 3 = Pin tip width of 3 thousands of an inch (0.003") which equals 75 µm; and XB (Extended Bubble) channel with a 1.25 µl uptake volume. An SMP15 pin is a Stealth Pin with a 0.015" (375 µm) wide tip and a standard 0.2 µl uptake channel. All 42 Stealth Pins use the same nomenclature and all are compatible with the three Stealth Printheads (see Table 2). Values are averages obtained using 500 fmol/µl Cy3-labeled oligonucleotide in 1X MSS printing solution on SuperAldehyde Substrates at 16°C and 50% relative humidity. Values can vary depending on the printing solution, substrate, temperature, humidity, motion control system, Z axis approach velocity, printing parameters, sample viscosity, and other variables. All pins have been durability tested beyond 1,000,000 printing cycles with no detectable mechanical changes to the tip, uptake channel, pin shaft, or collar. SMP2 and SMP2.5 series pins (red shading) produce spots ranging from 62.5-110 µm, and the small spot diameter and small tip dimensions of these pins are best used in conjunction with slightly slower Z axis approach velocities than the other Stealth pins. A maximum Z-axis velocity of 7.5 mm/sec is recommended for SMP2, SMP2B and SMP2XB pins and a maximum Z-axis velocity of 10 mm/sec is recommended for SMP2.5, SMP2.5B and SMP2.5XB pins.

Stealth Printhead



Stealth Printheads. All 42 Stealth Pins (see Table 1) fit interchangeably in the Stealth Printheads. (Left) Stealth 32 Pin Printhead (SPH32) shown as a front view. (Right) Stealth 48 Pin Printhead (SPH48) shown as a rear view. The two mounting screw ports allow easy attachment of Stealth Printheads to any high quality motion control system.


Table 2. Stealth Printhead Matrix.

Robodesign Stealth and Chipmaker Printheads



The Robodesign Stealth Printhead is designed to allow users to take advantage of ArrayIt Brand Stealth Micro Spotting Pins. It holds up to 48 Patented Stealth Micro Spotting Pins at 4.5mm center-to-center spacing. TeleChem's ArrayIt™ brand Stealth Pins and Printheads provides microarray manufacturers users with the highest quality; most advanced precision micro spotting technology available. The Robodesign Stealth and Chipmaker Printhead accommodates up to 48-patented Stealth or Chipmaker Style Micro Spotting Pins.

Table 3. Robodesign Stealth and Chipmaker Printheads

Stealth Custom Printhead for a Genetix Robot

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